Safety device for gas appliances



Dec. 16, 1941. s. KARRER EIAL 2,266,642

SAFETY DEVICE FOR GAS APPLIANCES Filed July 7, 1939 i V, 6 7 r r r M I ab I 1 3|WQMM5 61 /l/ i I SebasifwLfia/rer 6O 76 PaulL. 8662..

iulomm/qs Patented Dec. 16, 1941 2,266,642 SAFETY DEVICE FOR GASAPPLIANCES Sebastian Kan'er, Washington, D. 0., and Paul L. Beta,Baltimore, Md., assignors to Consolidated Gas ElectricLight and PowerCompany of Baltimore, Baltimore, Md., a corporation of MarylandApplication July 7, 1939, Serial No. 283,308

14 Claims.

This invention relates to safety devices for gas appliances, and moreparticularly to means which will operate automatically to prevent flowof gas to the appliance or appliances if an effort is made to initiatesuch flow while a gas valve or other outlet is open. The invention hasparticular utility in conjunction with prepayment gas meters, but aswill be apparent to those skilled in the art and as hereinafter pointedout, the invention may be applied to perform like functions in othercombinations involving gas appliances.

In prepayment gas meters a valve is ordinarily provided inside the metercase for operation by a coincontrolled device so that, upon deposit ofone or more coins, the valve is opened and will remain open until apredetermined quantity of gas has passed through the meter. When thisquantity has been used up the valve closes, and if any burner is inoperation at that time the flame is extinguished although the appliancecock is open. If another coin is then inserted without previouslyclosing the appliance cock unignited gas will escape and may beproductive of fire, explosion, gas poisoning or other dangerousconditions.

It is an object of this invention to provide a means for eliminating theaforesaid hazard in the use of prepayment gas meters.

A similar situation may arise when it is necessary to cut oil the gassupply at a main. Unless all burners are shut off individually in theaffected appliance or area, restoration of gas flow will result in gasescape from any burner which was-ignited at the time the gas supply wasdiscontinued. Thus if the supply main to a house is shut off it isnecessary to make certain that all burner cocks, as for example those onhot water heaters, be shut off before the gas supply is restored if ahazardous condition is to be avoided.

It is an object of this invention to provide a safety device which maybe associated with an individual gas appliance or with a plurality ofgas appliances in a given area to eliminate this necessity of firstvisiting all the burners and making sure that they are shut off beforethe gas supply is restored.

A further object of this invention is to provide prepayment gas meterswith means which may be readily incorporated in or associated with suchmeters for preventing flow of gas following an interruption of the gassupply unless all of the burners are turned off. I

Another object of this invention is to provide means which may beapplied to a gas supply conduit, whether that supplying an individualappliance or that supplying a plurality of appliances over a smaller orlarger area, which will prevent unsafe conditions arising frominterrupting the gas supply without first requiring that all burners bevisited to make sure that they have been shut off.

Another object of this invention is to provide a device of the typecharacterized which is simple in construction, compact, inexpensive to.manufacture and install, and highly efllcient in operation.

Other objects of this invention will appear as the description thereofproceeds.

The invention is capable of receiving a variety of mechanicalexpressions, several of which are shown on the accompanying drawing, butit is to be expressly understood that the drawing is for purposes ofillustration only and is not to be construed as a definition of thelimits of the invention, reference being had to the appended claims forthat purpose.

Referring in detail to the accompanying drawing, wherein the samereference characters are employed to designate corresponding parts inthe several flgures Fig. 1 is a somewhat schematic axial section showinga valve arrangement embodying the present invention and adapted to beincorporated in a prepayment gas meter;

Fig. 2 is an enlarged view of the valve operating means of Fig. 1;

Fig. 3 is a somewhat schematic axial section showing another embodimentof the invention adapted to be applied to a prepayment gas meter butemploying a diaphragm means for assisting both the valve closing andvalve opening forces of the device; and

Fig. 4 is a somewhat schematic axial section showing another embodimentof the invention which may be connected in the gas line ahead of aparticular appliance to be protected or which may be associated with agas main controlling the gas supply to a plurality of appliances over asmaller or larger area.

Referring first to the embodiment of Figs. 1 and 2, which shows astructure that may be readily incorporated in the interior of aprepayment gas meter, l0 designates a chamber which may be formed in thegas meter in any suitable way, the meter and its coin controlledmechanism being not illustrated, as the same constitute no part of thepresent invention except as herein indicated. Gas may enter the chamberII! from the main or supply line through inlet II' andleave the chamberI through outlet I2 on its way to the appliance or appliances controlledby said meter.

Formed within the chamber III in any suitable way is a valve seat I3with which cooperates a valve member I4 of any suitable form. Asillustrated, a metal to metal contact is provided between the valvemember I4 and its seat I3, although any other suitable type or characterof valve may be employed, as a valve disk of deformable material or avalve disk carrying an annulus of yieldable material for cooperationwith the valve seat. As illustrated, see particularly Fig. 2, valvemember I4 carries a plug I6 suitably attached thereto as by threadingand having a spring centering extension I6 projecting downwardlytherefrom as viewed in Figs. 1 and 2. Ifpreferred, however, member I orits equivalent may be formed integrally with the valve disk I4. MemberI5 is provided with an aperture I1 through which extends a stem I8 thathas formed on or attached to its inner or lower end as viewed in Figs. 1and 2 a suitable flanged or dished plate -I 9 between which and thevalve member I4 is disposed a coil spring 20. The bore of aperture I9 issomewhat larger than the cross section of the stem I8 so as to provide asurrounding annular bleeder passage through which gas may flow from theregion above the disk I4, as viewed in Figs. 1 and 2, and through saidannular space 2| to the chamber 22 below said valve disk.

Formed on or suitably attached to the opposite end of valve stem I8 is asecond valve member 23 adapted to cooperate with a valve seat 24surrounding the upper end of the aperture IT, as viewed in Fig. 2, andhere shown as formed on the plug I5, so that when valve member 23engages seat 24 flow of gas through the bleeder passage 2I is prevented.As illustrated, a metal to metal contact is also provided at this lastnamed valve, but as in the case of valve member I4, any other suitableconstruction of valve member may .be used, as by providing the disk 23with a deformable disk or annulus for engagement with the seat 24.Attached to valve disk 23 is a yoke 25 to which is pivoted a lever 26that is suitably mounted as by the pivot 21 and that is actuated by thecoin controlled mechanism of the gas meter.

As shown in Fig. 1, both valves are closed by the engagement of disk I4with its seat I3 and by the engagement of disk 23 with its seat 24, andlever 26 as shown in full lines is in that position which it assumesafter the predetermined quantity of gas has passed the meter so that gasflow is discontinued until an additional coin or coins are deposited inthe coin collecting device thereof. Upon inserting a coin in the coincollecting device, arm 26 is moved from its full line to its dotted lineposition as shown in Fig. 1. As yoke 25 is pivotally attached to lever26 disk 23 is lifted with respect to its seat 24, as shown in Fig. 2,and against the tension of the spring 20, the additional tension thusarising from the compression of the spring 20 tending to also lift valvemember I4 away from its seat I3. If all burners controlled by the deviceunder discussion are closed gas may flow through the bleed openingprovided by the annular passage 2| until it builds up such a pressure atthe underside of the disk I4 that, together with the compression ofspring 20, the disk I4 will be raised away from its seat I3 and gas mayflow to the appliance or appliances controlled by the meter.

Assume, however, that at the time the meter valve was closed a burnerwas in operation and the gas cook thereof has not since been closed:Atmospheric pressure will now exist in the chamber 22 due to the opengas cock, and the pressure of the gas on the upper face of the valvedisk I4 is more than suillcient to overcome the additional tension ofthe spring 20 arising from the 'actuation of the lever 26, spring 20being suitably designed so that the tension imposed thereby on the valvedisk I4 is less than the difference of pressure existing above and belowthe valve disk I 4 when any gas cook communicating with the outlet I2 isopen. Thus the valve I4 will remain on its seat I3 due to the differencein pressures above and below the valve disk I4 and only such gas canescape as will flow through the bleeder passage 2Iwhich may besufllcient to constitute a warning that gas is escaping but not sumcientto produce a dangerous condition.

As soon as all burners communicating with the outlet I2 are closed,however, the escape of gas through the bleeder opening 2| will result ina gradual increase in pressure in the chamber 22 until a pressure isreached such that the'tension of spring 20 will overbalance the seatingforce theretofore exerted on valve member I4 by said pressuredifference, whereupon spring 20 will raise valve member I4 and permitnormal flow of gas through the outlet I2. It is preferred that whenvalve disk I4 is open seat 24 reengages disk 23 so that valve member I4will not vibrate when in its open position. When the predeterminedquantity of gas has again been used up valve member I4 which has beenlowered toward its seat as rapidly as permitted by the movement of thearm 26, reaches a position wherein it will by snap action reengage itsseat I3 owing to the pressure changes arising from the decreasing portopening.

In the embodiment of Fig. 2 the force for holding the valve member incontact with its seat is only the difference in pressure on the twosides of the valve member I4 as modified by the action of the spring 20.Fig. 3 shows an embodiment which may also be incorporated in aprepayment gas meter and which is provided with a diaphragm or otheranalogous means to assist in holding the valve closed when an unsafecondition exists and to help unseat the valve when proper conditionsareestablished. The embodiment of Fig. 3 employs a chamber III, inlet II,outlet I2, valve seat I3, valve member I4, stem I8, spring seat I9,spring 2|), bleeder passage 2|, auxiliary valve disk 23, yoke 25 andlever 26 as in the embodiments of Figs. 1 and 2, these and associatedparts being shown as of the same construction and therefore furtherdetailed description thereof is unnecessary.

In the embodiment of Fig. 3, auxiliary chamber 30 is provided inassociation with the chamber ID in any suitable way, being shown asdefined by an annular wall 3| suitably attached to or integral with thewall of chamber I0. Suitably mounted on the annular wall 3| so as toform a gas-tight seal therewith is a diaphragm 32 of any suitable sizeand material, the same being shown as clamped to the edge of said wall3| by a plate 33 and screws 34. Attached to the center of said diaphragmis a stem 35, said stem being shown as having a head 36 and extendingthrough a pair of washers 31 and 36 between which the central portion ofthe diaphragm is compressed by a nut 39 mounted on a threaded portion ofthe stem 35. Washer 36 is shown as of inverted cup-shaped or dishedformation, and interposed between the same and the wall 40 ofthe'chamber It is a coil spring of'suitable tension to perform thefunction hereinafter described. Spring 4I may be centered or held in itsproper location by a lug 42 formed on or attached to the wall 40. Stem35 extends through an aperture 43 in the plate 33 which preferably makesonly a relatively small clearance with said stem for a reason to bereferred to, and the opposite end of said stem is preferably guided, soas to enforce rectilinear movement, by reception in the recess 44 of alug 45 suitably attached to or formed on the cover plate 48 of thechamber I 9.

Secured to the stem 35 at spaced points along its length suitablyselected to perform the functions next to be described are disks, pinsor other suitable actuating elements 41, 48 and 49. Pivotally mounted at50 and 5| on the\wall of the chamber III in any suitable way are levers52 and 53 shown as apertured for passage of the stem 35, lever 52beingoperatively related to member 41 and lever 53 extending between theoperating members 48 and 49. Lever 52 is disposed below the valve diskI4 as viewed in Fig. 3,

and lever 53 is disposed above said valve disk,

disk I4, as viewed in Fig. 3, by a bleeder passage. v

56 formed in any suitable way and thereby providing for theestablishment in the chamber 30 of the same pressure as exists in thechamber 22.

Assume that the amount of gas predetermined by a previously depositedcoin has already passed through the meter, so that lever has been movedto the full line position shown in Fig. 3, whereby valve members I4 and23, are both in closed position as shown and as explained in conjunctionwith the embodiments of Figs. 1 and 2. If anew coin is now deposited inthe meter, lever 28 will move from the solid line to the dotted lineposition, raising valve member 23 from its seat 24 and, as in theembodiment of Figs. 1 and 2, compressing spring 2|! to impose an initialopening tension on the valve member I4, although if preferred theopening and closing of the valve member may be dependent only on thepressure differential exerted on the diaphragm 32. If a burner has beenleft open at the time the flow of gas was discontinued, however, therewill be atmospheric pressure in the chamber 22, as in the embodiments ofFigs. 1 and 2, and the tension of the spring 20 owing to the appropriatedesign of said spring 29, is insufficient to overcome the difference inpres sure existing on the two sides of the valve member I4.

In this embodiment atmospheric pressure also exists in the chamber 30because of the bleeder opening 56, while gas pressure is acting inchamber III on the upper face of the diaphragm 32, as viewed in Fig. 3,so that said diaphragm is depressed against the tension of the spring4|, and stem engages member 49 with lever 53 which in turn engages theface of the valve member I4 to hold said valve member closed. Lifting ofthe valve member 23 permits a small leakage of gas through the bleederpassage 2|,

1 as in the embodiments of Figs. 1 and 2, but as sure cannot change inchambers 22 and 30 to alter the condition Just described.

' When all of the burners communicating with the outlet I2 are closed,however, the leakage of gas through the annular bleeder passage 2Iresults in pressure being built up in both chambers 22 and 30. Thisdecrease in the difference in pressure on the two sides of the valvemember I4 not only enablesspring 20 to move valve member I4, but thedecrease in the pressure differential on the two sides of the diaphragm32 results in coil spring 41 moving valve stem 35 upwardly and therebyfirst removing member 49 from lever 53 to release the lever 53 and thenengaging member 48 with'said lever 53 to positively move said leverupwardly out of the way of the valve member I4, while member 41simultaneously moves lever 52 to engage valve member I4 and assist thelatter in its opening movement. Hence in this embodiment as justdescribed the valve member- I4 is opened by the combined action of thesprings 20 and 4| when the pressure difference on the two sides of thevalve member I4 and the diaphragm 32 has been decreased by gas flowthrough the bleeder passages 2| and 56.

When a predetermined quantity of gas has passed lever 26 will again movefrom dotted to full line position, and the actuating force on said lever25 is sufficient to move the valve member M to its closed position eventhough lever 52 be in contact therewith, spring 4| being therebytensioned to assist in the next opening movement of the valve member I4if lever 26 is moved from full line to dotted line position while allburners are closed so that gas pressure rather than atmospheric pressureexists in the chambers 22 and 30. But if atmospheric pressure exists inchambers 22 and 30 the parts are moved to the position shown in Fig. 3and valve member I4 is held closed until all gas valves or other outletsare closed.

Should diaphragm 32 rupture for any reason full flow of gas to theburners would not follow, as only such gas could escape as can flowthrough the bleeder opening 56, and even this flow can be furtherreduced by making the clearance at 43 heretofore referred to of lesscross sectional area than the passage 56.

The embodiments of Fig. 4 is more particularly adapted for incorporationin a supply conduit either just ahead of a gas appliance or in a mainfor controlling a number of appliances although, as will be apparent,the construction now to be described could also by suitable adaptationbe incorporated within a prepayment gas meter analogously as theembodiments heretofore described could by suitable adaptation beemployed outside of the gas meter either ahead of an individualappliance or in a main leading to a plurality of appliances. In thisembodiment the casing 60 has an inlet BI and an outlet 62, andinteriorly the same is provided in any suitable way with a valve seat63. Cooperating with said valve seat 63 is a valve member 64 of anysuitable form and construction, such as heretofore referred to, andmounted on a diaphragm 65, as by 'a screw 66. Diaphragm is mounted inany suitable way, as by clamping its periphery between the flanges 61and 68 of the casing 30 and cover member 69 by means of screws 10. Thecentral portion of the diaphragm as illustrated is compressed betweenthe valve member 64 and a cup-shaped or dished washer II by the screw66, and interposed between said washer II and an adjustable plug 12threadedly mounted in an aperture 13 suitably formed on the cover 89 isa coil spring I4. By adjusting the position of the plug 12 the tensionof said spring 14 can be adjusted to provide for opening of the valvemember upon the occurrence of that difference in pressure on saiddiaphragm that is desired. Valve member 64 is shown as provided with ableeder opening I! as a means of communication between the chamber 16below the valve member 64, as viewed in Fig. 4, and the chamber 11beneath the diaphragm 85 and with which the outlet 62 communicates.Chamber 18 above the diaphragm is maintained at atmospheric pressure byany suitable vent, here shown as provided by an aperture 19 in the plug1!.

Assume that the inlet BI is in communication with any suitable main andthat the outlet 82 is in communication with any suitable meter or metersor other appliance or appliances. As long as gas pressure exists inchamber 'll diaphragm 65 is flexed upwardly, as viewed in Fig. 4,against the tension of the spring 14, by the difference in pressureacting on the two sides of said diaphragm. If for any reason the gaspressure is cut oiI at the inlet GI and any burner is in operation atthat time, atmospheric pressure is communicated to chamber 11 and spring14 causes the member 55 to flex downwardly as viewed in Fig. 4 andengage valve member 64 with said seat 63. When the gas pressure isrestored at the inlet 6|, still assuming there is an open outlet orburner in communication-with 62, atmospheric pressure will continue toexist in the chamber 11 and spring 14 will hold valve member 64 closedas long as such pressure condition exists. As soon as all outlets areclosed, however, gas pressure bleeding through the passage into chamber'II will reestablish excess pressure on the underside of said diaphragm65 is viewed in Fig. 4 and open the valve member 64 against the tensionof the spring 14, again permitting full flow of gas through the outlet52. If all of the outlets communicating with 62 are closed when the gaspressure is cut ofi at 6|, and remain closed, the diaphragm 65 will beautomatically flexed upwardly again, against the tension of the spring14, as soon as gas pressure is restored at 6|.

If for any reason diaphragm 65 should rupture gas can escape only aspermitted by the relatively small bleeder opening 15 and therefore nofull flow of gas is permitted.

It will therefore be perceived that in all of the embodiments discloseda device has been provided which is entirely automatic in operation andwhich is effective to stop the gas flow, except for such small leakageas can occur through the bleeder opening, if when gas flow is restoredafter a discontinuance any burner or other outlet in communication withthe device happens to be open, and only upon the closure of all burnersor outlets can gas flow be reestablished. No manually operable means areinvolved in the device and therefore it is impossible by manualresetting of any element, through carelessness or other wise, toreestablish gas flow as long as any gas valve in the line on the outletside of the device remains open. Devices have heretofore been proposedwhereby a predetermined drop of pressure in the gas main has resulted ina valve being closed, said valve being manually resettable andcontemplating that an authorized person will reset the valve when propergas pressure has been reestablished. But devices of this character arenot suitable for prepayment gas meters for example, because of thedanger that the householder may deposit a coin or manually reset thevalve without taking proper precautions to assure that all gas valveshave previously been closed. The present invention obviates thedangerous conditions that may arise from depositing a coin in aprepayment gas meter or otherwise restoring gas pressure without firstmaking certain that all gas valves are closed. as gas cannot flow to theburners as long as any burner or other outlet in communication with thesafety device is open-and this cannot be ch'anged by any operation of amanually manipulated element.

While the embodiments of the invention illustrated on the drawings havebeen described with considerable particularity, it is to be expresslyunderstood that the invention is not restricted thereto, as the same iscapable of receiving a variety of mechanical expressions, as will now beapparent to .those skilled in the art, while changes may be made in thedetails 01' construction, arrangement and proportion of parts bellows orother comparable elements may be used in the place of diaphragms, anysuitable construction of valves may be employed, etc., and certainfeatures may be used without other features, without departing from thespirit of this invention. Reference is therefore to be had to theappended claims for a definition of said invention.

What is claimed is:

1. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve between said chambersfor controlling the flow of gas therebetween, means operable from theexterior of said device to condition the same for opening said valve andmeans for automatically rendering said valve opening means incapable ofopening said valve if any outlet in communication with said outletchamber is open, said means including a bleeder passage between saidinlet and outlet chambers and means inoperable from the exterior of saiddevice and associated with said valve and effective to open the valveonly when gas pressure develops in said outlet chamber, by gas flowthrough said bleeder opening, when all outlets are closed.

2. In a. safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat to prevent flow or gas between said chambers, means forautomatically assuring that said valve member shall remain in closedposition if any outlet in communication with said outlet chamber is openwhen gas pressure is admitted to said inlet chamber, said meansincluding a bleeder passage between said inlet and outlet chambers,resilient means operable from the exterior of said device to bias saidvalve member toward open position, and automatic means inoperable fromthe exterior of said device for opening said valve member when gaspressure develops in said outlet chamber by reason of gas flow throughsaid bleeder passage when all outlets are closed and for preventingopening of said valve member when gas pressure cannot develop in saidoutlet chamber by reason of an open outlet connection.

3. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that after'closure said valvemember remains closed as long as said outlet chamber is below apredetermined pressure, said means including a bleeder passage betweensaid inlet and said outlet chambers, said valve memsaid bleeder passage,all of the outlets communieating with said outlet chamber are closed.

4. In a. safety device for gas appliances, in combination with meansproviding inlet and out= let chambers and a valve member cooperatingwith a valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that said valve member remainsclosed as long as said outlet chamber is below a predetermined pressure,said means in eluding a bleeder passage between said inlet outletchambers, diaphragm means subjected on its opposite sides respectivelyto the pressures in said inlet and said outlet chambers and cooper=ating with said valve member and actuated by a difference in pressure onthe opposite sides thereof, and resilient means cooperating with saiddiaphragm means for biasing said valve member toward open position, saiddiaphragm means being efiective to cause opening of said valve memberonly when gas pressure has developed in said outlet chamber, by reasonof gas flow through said bleeder passage, if all outlets incommunication with said outlet chamber are closed.

5. In a safety device for gas appliances, in combination with meansroviding inlet and outlet chambers and a valve member cooperating with avalve seat for controlling the flow of gas between said chambers, meansautomatically operative to assure that said valve member remains closedas long as said outlet chamber is below a predetermined pressure, saidmeans including a bleeder passage between said inlet and outletchambers, a diaphragm subjected to the pressure in said inlet and saidoutlet chambers, valve operating members operatively connecting saidvalve member with said diaphragm, resilient means cooperating with saiddiaphragm to bias said diaphragm toward open position of said valve, andresilient means for biasing said valve member toward open position butautomatically operable to open said valve member only when gas pressure,by reason of gas flow through said bleeder passage, develops in saidoutlet chamber.

6. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow oi gas between s id chambers,means automatically operative to assure that after closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open, said means including a bleeder passage betweensaid inlet and outlet chambers, a valve stem on which said valve memberis movable, a, spring reacting between said valve member and said valvestem. and means for compressing said spring to bias said valve membertoward open position, the eflect of said spring being insuillcient toovercome the diflerence in pressure on the two sides 01' said valvemember unless gas pressure has developedin said outlet chamber, byreason of gas flowthrough said bleeder passage, as a result of alloutlets communicating with said outliet chamber being closed and saidspring when biased being operative to'open said valve member when saidgas pressure has devel-.

oped in said outlet chamber.

'1. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow 01 gas between said chambers,means automatically operative to assure that after closure said valvemember remains closed as long as any outlet in communicationwith saidoutlet chamber is open, said means including a bleeder passage betweensaid inlet and outlet chambers, a diaphragm sub iected at its oppositesides respectively to the pressure in said inlet and outlet chambers andoperable to move said valve member, and a spring cooperating with saiddiaphragm, said diaphragm and spring being effective to open said valvemember only it the gas pressure in said outlet chamber, by reason oi gasiiow through said bleeder passage, is above atmospheric pressure as aresult oi all outlets in communication with said outlet chamber beingclosed.

8. In a safety device for gas appliances, in. combination with meansproviding inlet and out= let chambers and a valve member cooperatingwith a valve seat for controlling the flow of gas between said chambtrs, means automatically operative to assure that after closure saidvalve member remains closed as long as any outlet in communication withsaid outlet chamber is open, said means being inoperable from theexterior 01' said device and including a bleeder passage between saidinlet and outlet chambers, a diaphragm cooperating with said valvemember and subjected on its opposite sides respectively to the pressurein said inlet and said outlet chambers, and resilient means cooperatingwith said diaphragm for biasing said valve member toward open positionbut only operable to open said valve member when gas pressuredevelops-in said outlet chamber by how through said bleeder passage itall outlets in communication with said outlet chambers are closed.

9. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that after closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open, said means including a bleeder passage betweensaid inlet and outlet chambers, said valve member being subjected at itsopposite faces to the pressures in said inlet and said outlet chambers,a spring cooperating with said valve member, and means for imposing atension on said spring to bias the same in opening direction, thetension ofsaid spring being insuflicient to open said valve member ifthe outlet chamber is subjected to atmospheric pressure but operative tomove said valve member to open position when gas pressure develops insaid outlet chamber by flow through said bleeder passage ii all outletscommunicating with said outlet chamber are closed, said valve openingmeans being inoperative to open said valve from the exterior of saiddevice in the absence 01' said gas pressure in the outlet chamber.

10. In a safety device for gas appliances. in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that alter closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open, said means including a bleeder passage betweensaid inlet and outlet chambers, a diaphragm subjected on its oppositesides respectively to the pressures of said inlet chamber and saidoutlet chamber, and arms interposed between said diaphragm and saidvalve member and cooperating with opposed faces of said valve member,said arms being actuated by the ilexure of said diaphragm under varyingpressure diflerences at the two sides oi said diaphragm for urging saidvalve member toward open or toward closed po-.

sition.

11. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the now or gas between said chambers, meansautomatically operative to assure that after closure said valve memberremains closed as long as any outlet in ommunication with said outletchamber is open, said means including a bleeder passage between saidinlet and outlet chambers, a diaphragm subjected at its opposite sidesto the pressure in said inlet and said outlet chambers, resilient meanscooperating with said diaphragm, and means actuated by said diaphragmand cooperating with said valve member, said diaphragm being actuatedagainst the tension or said resilient means to urge said valve membertoward closed position 11' said outlet chamber is substantially atatmospheric pressure and said resilient means cooperating with saiddiaphragm to urge said valve member toward open position it gas pressuredevelops in said outlet chamber by reason of gas llow through saidbleeder passage.

12. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that after closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open, said means including a bleeder passage betweensaid inlet and outlet chambers, said valve member being subjected on itsopposite sides respectively to'the pressures in said inlet and saidoutlet chambers, and resilient means operable externally oi said deviceand adapted to bias said valve member toward open position and automaticmeans inoperable from the exterior of said device for opening said valvemember by a decrease in the diiierence in pressure in said inlet withsaid outlet chamber are closed.

13. In a safety device'ior gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow of gas between said chambers,means automatically operative to assure that aiter closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open.

said means including a bleeder passage between said inlet and outletchambers, premure operated means subjected on opposite sidesrespectively to the pressures in said inlet and said outlet chambers,means for actuating said valve member from said pressure operated means,and resilient means biasing said pressure operated means toward openposition or said valve member whereby said valve member is held inclosed position when said outlet chamber is subjected substantialy toatmospheric pressure and said valve member is urged toward open positionwhen gas pressure develops in said outlet chamber by reason or gas flowthrough said bleeder passage.

14. In a safety device for gas appliances, in combination with meansproviding inlet and outlet chambers and a valve member cooperating witha valve seat for controlling the flow 01' gas between said chambers,means automatically operative to assure that alter closure said valvemember remains closed as long as any outlet in communication with saidoutlet chamber is open, said means including a bleeder passage betweensaidinlet and outlet chambers, a valve'controlling said bleeder passage.a diaphragm subjected on its opposite sides respectively to thepressures in said inlet chamber and said outlet chamber, a

spring normally urging said diaphragm in one,

direction, means for opening the valve in said bleeder passage andbiasing said valve member toward open position, and means actuated bysaid diaphragm and cooperating with said valve member for moving saidvalve member toward open position only when the pressure on the outletside of said diaphragm is that developed by reason of gas flow throughsaid bleeder passage when all outlets communicating with said outletchamber are closed.

. SEBASTIAN KARRER.

PAUL L. Bil-I2.

